由于盜獵猖獗,，大象正面臨著滅絕的威脅，科學(xué)家們預(yù)測如果不采取有力的措施來控制這種行為,，大象將于2020年從地球上消失,。
8月，最新出版的《保護生物學(xué)》上刊登了美國華盛頓大學(xué)生物教授塞繆爾·瓦塞爾（Samuel Wasser）的一篇文章,。在這篇文章中,，塞繆爾教授指出，在上個世紀八十年代,，由于非法象牙貿(mào)易猖獗,，非洲野生大象瀕于滅絕。聯(lián)合國因此于1989年通過決議，在全球范圍內(nèi)禁止一切象牙貿(mào)易活動,。不過盜獵大象的行為并沒有因此停止,，反而更加猖獗。根據(jù)最新公布的一份調(diào)查數(shù)據(jù)顯示,，目前在非洲，每年大約有8%的大象成為盜獵者的犧牲品,。這個比例比20年前實施禁獵措施時的7.4%還要高,。塞繆爾教授說，更為嚴重的是,，20年前的比例是基于100萬頭大象得出來的數(shù)據(jù),，而如今8%這個數(shù)據(jù)是基于47萬頭大象計算出來的結(jié)果。如果人們不采取有力的措施來控制這種行為,，到2020年野生大象將從地球上消失,。
塞繆爾教授指出，之所以出現(xiàn)這種情況,，一方面是由于象牙需求量急劇上升使得盜獵者為謀求巨額利潤而瘋狂獵殺大象,，另一方面是由于相關(guān)政府對盜獵大象行為采取了容忍的態(tài)度。目前,，以日本為首的亞洲市場對象牙的需求量非常旺盛,，其次就是美國。非法象牙貿(mào)易在這些地方非常猖獗,，巨大的利潤使得許多盜獵者不惜鋌而走險瘋狂的獵殺大象,。而象牙作為一項高利潤 、低風險的產(chǎn)業(yè),，給許多非洲國家?guī)砹司揞~的財政收入,，所以有些國家政府對盜獵大象的行為采取了容忍的態(tài)度。
塞繆爾教授表示,，要保護大象最有效的辦法的是切斷非法象牙貿(mào)易的源頭,，其次各國要采取有力的措施來打擊盜獵大象的行為。塞繆爾和他的研究小組開發(fā)出一種技術(shù),，可以通過檢測象牙的DNA來判斷這些象牙來自何處,。塞繆爾教授說，目前非法象牙貿(mào)易一個最主要的特點就是象牙盜取地和交易地點不一樣,，他說這樣做是盜獵者為了躲避法律的懲罰,。舉例來說，2002年在新加坡截獲的6.5噸非法象牙是從馬拉維出口的,，而DNA檢測技術(shù)卻顯示這批大象是來自贊比亞,。因此，要阻止日益猖獗的非法象牙貿(mào)易就要從源頭上切斷它，當然最重要的是當?shù)卣芊e極采取有效措施打擊這種行為,。
塞繆爾教授指出,，大象體型龐大，有80個人的重量,，但它們的視力卻很弱,，只能看清100米以內(nèi)的景物，所以它對其他動物及人類沒有很大的威脅性,，反而成了人類捕殺的對象,。野生大象壽命有70年，但現(xiàn)在許多大象卻因食物的缺乏,，棲息地的破壞,，壽命減少到了15年，再加上人類的瘋狂獵殺,，大象的生存狀況已經(jīng)惡劣了,，人們對此要有清醒的認識。否則到了2020年,，除了圈養(yǎng)在籠子里的大象之外,，我們再也看不到野生的大象了。（生物谷Bioon.com）
生物谷推薦原始出處：
Conservation Biology,，Volume 22 Issue 4, Pages 1065 - 1071,，SAMUEL K. WASSER, MATTHEW STEPHENS
Combating the Illegal Trade in African Elephant Ivory with DNA Forensics
Abstract: International wildlife crime is burgeoning in this climate of global trade. We contend that the most effective way to contain this illegal trade is to determine where the wildlife is being removed. This allows authorities to direct law enforcement to poaching hot spots, potentially stops trade before the wildlife is actually killed, prevents countries from denying their poaching problems at home, and thwarts trade before it enters into an increasingly complex web of international criminal activity. Forensic tools have been limited in their ability to determine product origin because the information they can provide typically begins only at the point of shipment. DNA assignment analyses can determine product origin, but its use has been limited by the inability to assign samples to locations where reference samples do not exist. We applied new DNA assignment methods that can determine the geographic origin(s) of wildlife products from anywhere within its range. We used these methods to examine the geographic origin(s) of 2 strings of seizures involving large volumes of elephant ivory, 1 string seized in Singapore and Malawi and the other in Hong Kong and Cameroon. These ivory traffickers may comprise 2 of the largest poaching rings in Africa. In both cases all ivory seized in the string had common origins, which indicates that crime syndicates are targeting specific populations for intense exploitation. This result contradicts the dominant belief that dealers are using a decentralized plan of procuring ivory stocks as they became available across Africa. Large quantities of ivory were then moved, in multiple shipments, through an intermediate country prior to shipment to Asia, as a risk-reduction strategy that distances the dealer from the poaching locale. These smuggling strategies could not have been detected by forensic information, which typically begins only at the shipping source.
